Facile fabrication of novel cobalt-based carbonaceous coatings on nickel-titanium alloy fiber substrate for selective solid-phase microextraction

Fabrication of selective adsorption coatings plays a crucial role in solid-phase microextraction(SPME).Herein,new strategies were developed for the in-situ fabrication of novel cobalt-based carbonaceous coatings on the nickel-titanium alloy(Ni Ti)fiber substrate using ZIF-67 as a precursor and template through the chemical reaction of ZIF-67 with glucose,dopamine(DA)and melamine,respectively.The adsorption performance of the resulting coatings was evaluated using representative aromatic compounds coupled to high-performance liquid chromatography(HPLC)with ultraviolet detection(HPLC-UV).The results clearly demonstrated that the adsorption selectivity was subject to the surface elemental composition of the fiber coatings.The cobalt and nitrogen co-doped carbonaceous coating showed better adsorption selectivity for ultraviolet filters.In contrast,the cobalt-doped carbonaceous coating exhibited higher adsorption selectivity for polycyclic aromatic hydrocarbons.The fabricated fibers present higher mechanical stability and higher adsorption capability for model analytes than the commercial polydimethylsiloxane and polyacrylate fibers.These new strategies will continue to expand the Ni Ti fibers as versatile fiber substrates for metal-organic frameworks(MOFs)-derived coating materials with controllable nanostructures and tunable properties.